Thermosensitive recording material

Abstract

A thermosensitive recording material is disclosed, which comprises a colorless or light-colored coloring material, and a color developer capable of inducing color formation in the colorless or light-colored coloring material upon application of heat thereto, in which the color developer is a phenolic material of the formula ##STR1## wherein R is an alkylene group selected from the group consisting of an alkylene group having 1 to 10 carbon atoms; an alkylene group having 1 to 8 carbon atoms which are not directly bonded to S in the formula, with 1 to 3 carboxylic groups contained therein; and an alkylene group having 2 to 15 carbon atoms, with 1 to 5 ether bonds contained therein.

What is claimed is: 
     
       1. In a thermosensitive recording material comprising a colorless or light-colored coloring material, a color developer capable of inducing color formation in said colorless or light-colored coloring material upon application of heat thereto, support means for supporting said coloring material and said color developer so that said color formation can be induced, the improvement wherein said color developer is a phenolic material of the formula ##STR30## wherein R is selected from the group consisting of an alkylene group having 1 to 10 carbon atoms; an alkylene group having 1 to 8 carbon atoms and containing 1 to 3 carbonyl groups which are not directly bonded to S in the formula; and an alkylene group having 2 to 15 carbon atoms and containing 1 to 5 ether bonds. 
     
     
       2. A thermosensitive recording material as claimed in claim 1, wherein R is an alkylene group having 2 to 15 carbon atoms, and containing 1 to 5 ether bonds; and said colorless or light-colored coloring material is a fluoran compound of the formula ##STR31## wherein R 1  and R 2  each represent an alkyl group having 1 to 6 carbon atoms or a cyclohexyl group; R 3  represents an alkyl group having 1 to 2 carbon atoms; and n is an integer of 0 to 1. 
     
     
       3. A thermosensitive recording material as claimed in claim 1, wherein the amount of said color developer is 1 to 6 times the amount of said colorless or light-colored coloring material. 
     
     
       4. In a thermosensitive recording material comprising a support, a thermosensitive recording layer on said support, said thermosensitive recording layer containing a binder, a colorless or light-colored coloring material and a color developer capable of inducing color formation in said colorless or light-colored coloring material upon application of heat thereto, the improvement wherein said color developer is a phenolic material of the formula ##STR32## wherein R is selected from the group consisting of an alkylene group having 1 to 10 carbon atoms; an alkylene group having 1 to 8 carbon atoms and containing 1 to 3 carbonyl groups which are not directly bonded to S in the formula; and an alkylene group having 2 to 15 carbon atoms and containing 1 to 5 ether bonds. 
     
     
       5. A thermosensitive recording material as claimed in claim 4 in which said thermosensitive recording layer is comprised of a first sub-layer containing said colorless or light-colored coloring material and a second sub-layer containing said color developer, one of said sub-layers being overlaid on the other of said sub-layers. 
     
     
       6. In a thermosensitive recording material comprising a first support having a first layer coated thereon, said first layer containing a first binder and a colorless or light-colored coloring material, a second support having a second layer coated thereon, said second layer containing a second binder and a color developer capable of inducing color formation in said colorless or light-colored coloring material upon application of heat thereto, the improvement wherein said color developer is a phenolic material of the formula ##STR33## wherein R is selected from the group consisting of an alkylene group having 1 to 10 carbon atoms; an alkylene group having 1 to 8 carbon atoms and containing 1 to 3 carbonyl groups which are not directly bonded to S in the formula; and an alkylene group having 2 to 15 carbon atoms and containing 1 to 5 ether bonds.